1. Field
This invention relates generally to the field of adjustable beds and more particularly to a structure incorporating a mating tension member extending from a support bar engaged on a surface of a mattress support element inset from an edge to the underside of the mattress adjacent a companion edge for tension the mattress to prevent “lift” in the mattress due to its rigidity when flexed by the articulating support elements.
2. Description of the Related Art
Articulating beds have long been used in hospital and healthcare facilities to allow positioning of a patient in a reclining position, sitting position, elevated leg position or combinations of these positions. General usage of articulating beds has been rapidly expanding due to the comfort and convenience available from adjusting the bed to desired positions for reading, general relaxation or sleeping.
The mattress employed with an articulating bed is typically a dense foam construction for adequate support and comfort of the user. Due to the relative rigidity of the foam, when the bed is articulated the mattress tends to resist bending, at least to a degree, and rises from one or more support surfaces on the structure of the bed. This rising effect can be deleterious since relative support is lost beneath the elevated portion and addition of weight may cause a rapid shift in position which is undesirable. Additionally, accurate positioning of the bed is difficult since mattress position may shift.
Prior art articulating bed systems employ rigid frame elements extending from the bed support structure at the foot of the mattress to retain the mattress over the articulated frame as disclosed in copending U.S. patent application Ser. No. 12/154,509 filed on May 23, 2008 issued as U.S. Pat. No. 7,930,780 on Apr. 26, 2011 entitled ADJUSTABLE BED FRAME ASSEMBLY having a common assignee with the present invention. While effective in maintaining the longitudinal and lateral position of the mattress, these prior art devices may interfere with applying bedding to the mattress, particularly fitted sheets rendering making the bed somewhat difficult. Additionally, such retention devices may allow lateral motion of the mattress during change of articulated position.
It is therefore desirable to provide a retention system for the mattress on an articulating bed which restrains the mattress for longitudinal motion and allows easy make up of the bed with bedding including fitted sheets.